[The dry eye. Current concepts on classification, diagnostics, and pathogenesis].

The etiology of dysfunctional tear syndrome ("dry eye") is multifactorial and complex. Recent evidence suggests an important role of androgens in regulating tear film secretion onto the ocular surface. In addition, inflammatory processes of the ocular surface seem to be the common final pathway of all chronic forms of dry eye. Novel concepts of pathogenesis and state-of-the-art diagnostic tools are discussed. In vivo confocal microscopy allows quantification of ocular surface inflammatory cells. This is of increasing importance for evaluation of anti-inflammatory treatments in dry eye patients.